


Unconventional

by Siennis



Category: Teen Wolf (TV)
Genre: Derek and Stiles are Mates, Extremely Underage, M/M, Parent/Child Incest, Uncle/Nephew Incest, and related
Language: English
Status: Completed
Published: 2015-01-15
Updated: 2015-01-15
Packaged: 2018-03-07 15:33:21
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 9,334
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3176849
Author URL: https://archiveofourown.org/users/Siennis/pseuds/Siennis
Summary: <blockquote class="userstuff">
              <p>Fourteen year old Derek Hale is convinced to raise his sisters child as his own son. Complicated enough right? Add in the fact that the child is also his Mate and... well.</p>
            </blockquote>





	Unconventional

**Author's Note:**

> Un-beta'd older fic of mine. Also, my first finished work in years. I'm sorry for this.  
>  Heed the tags, there is some extreme underage in this (Stiles is 6 at first sexual content)
> 
> DISCLAIMER: This work of fiction is just that, fiction. I absolutely do NOT condone this in real life.

**

_Beacon Hills, CA  
1995, November 11th_

Derek Hale was glad that it was his fourteenth birthday, and not only because of the presents and the cake (although he was pretty happy about those things as well, as any teenager would be) and his extended family coming to visit, but because his older sister, Laura, had promised to email him today and finally tell him what was going on with her, the reason why she ran away ten months ago.

His Mom, Talia Hale (Alpha to the Hale pack) had theorized that it had something to do with the boy she had been seeing "in secret" (it was really hard to keep a secret from a family of werewolves, and when you come home from a friends house smelling of sex and old spice, it was pretty obvious you were seeing someone, even if you refused to admit to it) but although everyone in school was worried about Laura, and asked Derek questions about her all the time, nobody had smelled guilty or overly concerned about where she had went, so that theory kind of went out the window. 

Derek kind of wondered if it was something to do with the family, if she felt pressured because Mom had began prepping her to take over as Alpha when Mom died. The training was more mental then physical (physical training was something Laura could ace in her sleep) and Laura had been struggling recently, trying to remember everything that an Alpha did-or-didn't-do in a certain situation. She'd stormed out of Mom's study on more then one occasion, ranting about her stupid lessons, about how being a werewolf was too stressful when you were a teenager and why didn't anybody just _understand_ that?

Dad was usually the one to calm Laura down after a rant like that. That was Dad's special skill, Derek was certain. He could keep a cool and calm head about any situation, whether it was rouge Omega's coming through the town or his ranting eighteen year old daughter.

Dad was pretty cool.

So when Derek had finally caved and emailed Laura a few months back without much hope of a reply, and she told him that she would send him the full story on his birthday, he quickly began counting down the days, eager for the reason why left her home, pack and life behind.

It was now his birthday. His family had all given him hugs and presents, they'd eaten the delicious cake his Uncle Peter baked and decorated himself and now Derek was sitting at the family computer, staring at the screen and hitting the refresh button every minute, waiting for the email to come in.

Seriously, what was taking Laura so long? Did she mean she'd wait until 11:59 PM to send the stupid email? It was nearly nine o'clock already, he'd been fourteen all day and he really wanted to find out what was going on.

When the email finally ( _finally_ ) came and Derek clicked quickly on it and began to scan the contents, he kind of wished he hadn't been waiting for it.

He kind of wished he could ignore the entire thing, go back to celebrating his birthday and play Super Nintendo with Uncle Peter (who always talked trash and made Derek laugh).

Laura... had gone away to have a baby, apparently. She'd ran the moment the pregnancy test came up positive because the boy, or rather _man_ she'd been seeing was not only way older then she was, but also married and a deputy within the police department. Deputy John Stilinski. Married to the school's amazing librarian Claudia, who always had something nice to say to Derek and hid his favourite books whenever they came in.

Laura fell in love with Deputy Stilinski, she said, but because he was married she knew that it could never really happen between them and she didn't want to drag a child into it, so she ran without telling him she was pregnant and potentially ruining his marriage, giving birth half way across the world. In Poland of all places.

And, oh God it got worse, she was coming home with the baby in a few months (once she thought the little boy could handle the flight) and was begging Derek to not only cover for her (which of course he would, he loved his sister) but to _lie to his parents and say the baby was his_!

What the _hell_ , Laura! 

She knew better then anybody that you couldn't just lie to your werewolf parents! How the hell did she expect to pass of a baby as Derek's?

He emailed back quickly, mostly questioning her sanity if she thought a fourteen year old could not only raise a tiny little baby, but lie to their parents about it? Was she insane?

Laura, being the stupid big sister she was, only emailed him back a few short words.

**Please, Derek. I need your help. Trust me.**

Derek sighed, laying his head on the keyboard, filling the blank reply with the random letters.

Shit. What was he going to do?

**

Derek and Laura emailed frequently over the next month (which was safer then the phone, since nobody could overhear an email), trying to figure out just how to get the blatant lie past their parents and Laura telling Derek about the little boy that would soon be his. Apparently Laura decided to start the boys life off with a piece of torture that would last his entire life.

She named the baby Wielisław. 

Wielisław!

Apparently that was the name of the Alpha of the pack in Poland that took care of her (and was helping take care of the baby) and it was only right that she name the baby after him. And, she told him, it apparently meant "great glory" or something. Derek just thought she was a cruel woman and wondered how he was supposed to make anyone believe he'd name his son (fuck, his soon to be _son_ ) something that he couldn't pronounce.

Laura helpfully told him how to pronounce it and told him to make up some story about how the baby had that name, which meant that Derek had even more lies to try and get around his parents.

Great. He really loved his life right now.

Not.

**

With some reluctant help and training from the pack emissary, Dr Deaton, Derek finally felt like he was ready to ruin his entire life. Or ready enough anyway. He emailed Laura that, and she told him she'd be home in two weeks time.

She also felt like Derek should at least meet Wielisław ("vye-LEE-swahf, Derek, remember!") before they brought the baby home with their carefully crafted story, so Derek told his parents that he was heading out to meet up with some people (not a lie) and that he'd be home later (still not a lie) and took a cab to the coffee shop Laura told him to be at when her flight got in.

He shifted and fidgeted so much for the half hour he had to wait that Derek was pretty sure the woman at the counter thought that he was going to meet his dealer or something, a fact probably not helped by the leather jacket his Dad got him for his birthday. He didn't really look like a bad kid, per say, but he did look like a twitchy kid, so he understood her wariness.

He smelt them first. Over the scent of coffee and random people, he could smell the home-happy-pack scent his entire family smelt like with the dash of snark and fire that made up Laura, with the underlying hint of something wonderful that made Derek perk up in his seat.

He had never smelt anything like that before! It smelt like... honey and dancing and laughter and the first full moon of summer. He couldn't explain it, but it just. It smelt _right_.

Then he heard their heartbeats and Derek felt his own stutter past a beat before settling along side the tiny one, the calm one. The one belonging to the baby, to Wielisław. His son.

He frowned. That wasn't right. He'd heard stories of a wolves heartbeat changing to match someone else's, but in the tales his Mom told him, it was never family, it always happened with their match, their Mate. The one person or wolf in all the world that they were meant to be with, to protect and love.

 

Oh.

_Oh_.

Oh no. Oh no, this was bad. This was Bad with a capital B. If the stories he'd been raised on about Mates was true (and it probably was, his parents were Mates) then the little boy, his nephew that was now his son, was also his _Mate_.

He couldn't do this, he couldn't raise Wielisław as his son while knowing that he was the one person in the world for him, the one that he was supposed to be with for the rest of time itself (never mind that fact that he was already his blood, his _nephew_ , how was he supposed to...)

Laura and Wielisław came in, and Derek felt his eyes widen, his breath catch in his throat, upon the little bundle sleeping in his big sisters arms.

Laura smiled hesitantly at him, seeing his stricken face and sitting down at the back table he'd secured and turned her arms slowly to show Derek Wielisław's little face. "Derek. Meet Wielisław."

"He's..." Derek stuttered, eyes roaming over his Mates-no, his sons-face. Adorable little upturned nose, freckles and moles he probably got from Deputy Stilinski, a wild little tuft of light brown hair and a Batman pacifier. "God, he's..."

Laura chuckled a little, mistaking his panic at seeing his nephew/son/Mate as seeing his nephew/son for the first time (at least she was slightly right). "He's adorable isn't he? Doesn't look much like me, anyway, he really looks like his Dad." She smiled a little at the baby, then back up at Derek who couldn't take his eyes off the baby. Her smile dropped seeing the real panic. "Derek?"

"I... just... He's _mine_ ," Derek said, licking his lips, having to say it without actually saying a thing.

Laura brightened. "Oh good, Deaton has been helping with your lying. I didn't hear a single stutter in your heartbeat! We can actually do this." She stood back up, coming over to Derek (oh god, why was she coming over to him?) and gently holding out the baby. Her baby. His baby. His. "Hold him, Der. Get used to the feeling so that way Mom and Dad won't pick up on the panic."

Derek swallowed, arms itching to hold his tiny Mate (fuck, he was way to young to be dealing with this). He still hesitated. "Laura..."

"You promised me," she reminded him softly, just as the bundle began to stir. They both looked at Wielisław as he blinked open bright amber eyes. Derek stared. Wielisław stared back. "Oh, he likes you!" She said, happily, "Now hold him." She passed him over without given Derek another chance to protest.

Wielisław kicked a little at the transfer into Derek's arms but he settled against his chest quick enough, and Derek felt his wolf howl in triumph. His Mate was in his arms. Even if his Mate was a baby that he was roped into raising as his own son, it still felt right to be holding him. It was a wolves job to protect and care for their Mate, and what better way to then to have him close at hand at all times?

It was going to cause problems when Derek's wolf was ready to claim the boy but at the moment, all Derek could think of at that very moment was loving this little boy in his arms.

"He's mine," Derek whispered again, ignoring everything around him as he pressed his nose to Wielisław's hair and took a deep breath, eyes closing in bliss at the scent of his son. His Mate.

_Mate_ , his wolf agreed happily.

**

The easiest part of everything, Derek thought after, was probably telling their parents the finely crafted story the two siblings had decided on. All it took was some careful wording as to not outright lie (which was easier now, since Wielisław _was_ Derek's, just not in the way everyone thought).

To his parents and the rest of the world from here on out, Derek had gotten an older girl pregnant, said girl then ran to Poland to have the baby, naming him after the father of the family she stayed with, emailed Derek to tell him, Laura flew out the collect the baby and bring him home and Derek was going to raise the baby (calling his Stiles as a nod to the babies real Dad), end of.

"But Derek," Mom protested from her seat at the head of the table, Dad at her right and Laura on her left, "You're only fourteen. Wouldn't it be a better idea to... let someone else raise him?"

Derek shook his head, lips pressed to Wielisław(Stiles)'s hair as the baby blinked around at everyone but didn't fuss. "He's mine, Mom. I can't let someone else raise him knowing what I know now. I need to keep him safe," he told her, "and what better way then with the pack? With people that will love him and provide for him?"

"School?" she asked, nails clicking on the table.

Derek shrugged, "I don't know. I can take time off?" But Mom was already shaking her head.

"No, no that won't do. I guess we can look after him while you're there. Derek... are you sure you want to do this? It's not like having a pet. This is a child, someone that is going to depend on you for years to come. You'll need to provide for him. Babies change your lives and you need to be absolutely sure."

Derek nodded, knowing that he would do anything for the baby in his arms. "He's mine."

Mom sighed and Derek shared a small smile with Laura, knowing that their Mom had caved.

**

_Beacon Hills, CA  
2001, Stiles' Sixth Birthday_

"Dad! _Dad_! _**DAD!**_!"

Derek, almost twenty, allowed himself a little sigh as the little demon he called Stiles yelled in his ear at--he blinked over at the clock on his end table--seven a.m. Jesus, it was too early to deal with his little ADHD hellion.

"Stiles," he groaned into his pillow as his son jumped on his back, continuing to call his name. "It's too early, pup. Back to sleep."

"But _daaaaaad_ , it's my birthday!" Stiles kept tugging at Derek's arm. "That means birthday pancakes! Pancakes _with_ bacon!"

Derek sighed again. He knew that he wasn't going to be able to talk Stiles back into bed when there was the promise of pancakes and bacon in his immediate future. He let himself lay there for another minute of Stiles' pleading and begging in his ear, shifting to sit and wiggle on Derek's back (which made Derek twitch a little in ways he tried valiantly to ignore) and pull at Derek's dark hair.

He let out a playful growl, making Stiles squeal in delight, before twisting and gently flipping his son back onto the bed, nuzzling into the soft skin of his neck. Stiles giggled and squirmed, tilting his head back as Derek's stubble tickled his throat and chin.

"Dad," he laughed, slapping ineffectually at Derek's wide shoulders, "bacon pancakes first! Then birthday cuddles!"

Derek hummed, breathing in the scent of his son and Mate, smiling against the exposed throat. "Birthday cuddles are always first," he replied solemnly, "as well as birthday tickles!"

"Nooooo!" Stiles howled happily as Derek lent back on his knees, tickling his boy mercilessly. "Nonononono, daddy, stop!"

Derek laughed loudly, pinching Stiles' side before rolling off the bed, tossing the ecstatic boy effortlessly over his shoulder. "C'mon, bath first and then I'll make your birthday bacon pancakes, 'kay pup?"

"'Kay," Stiles agreed easily, slapping at Derek's shoulder blades and tracing the tattoo between them with his small hands. "Love bath time," he added.

Derek chuckled, placing Stiles gently on the toilets closed lid, ruffling his wild brown hair before turning to start the water. "I know you do. Batman bubbles today?"

"Yes!" Stiles crowed, clapping and wiggling. Batman bubbles were only for special occasions because the sweet smell tended to make Derek's sensitive nose hurt. "Batman is the best!"

Derek tested the water, making sure it was no hotter then his own skin temperature (and therefor the perfect temp for his human son) before turning with a fake frown, hands on his hips. "I thought that _I_ was the best!"

Stiles rolled his eyes, as though his Dad was the silliest person in the entire world and Derek had to grin again. "You are the best _Dad_ ," he emphasized. "Batman is the best everything else."

"Ah," Derek nodded, dropping a kiss on his soft hair, "that makes perfect sense."

"Duh," Stiles agreed.

Derek stood, gently tugging Stiles to do the same. "Alright pup, we have time for a quick bath and breakfast before school, so you get to pick today. Bath with Dad in it, or bath with Dad out?"

Stiles pursed his little lips, scrunching his upturned nose and stared at Derek. He nodded. "Bath with Dad today," he decided and Derek couldn't stop the happy grin (nor the guilty, sick little curl in his gut).

He loved baths with Stiles, had been having them together since Stiles was just a baby. Of course, now that Stiles was getting older (Jesus, six years old today), Derek would often give Stiles the choice of Derek getting into the tub with him or sitting outside of it and helping him wash and rinse. Stiles usually chose to keep bathing together and Derek couldn't help the feeling he got when he was able to cradle his son-Mate-in his big arms and keep his safe (even if it was only safe from the possibility of drowning in the tub).

"Arms up," Derek instructed, already tugging at the sleep shirt Laura had picked out for his boy and pulling it smoothly off. "Okay, hold onto my arm and lift one foot. Good, okay and now the other. Good," Derek said, tugging Stiles' sleep pants off. "Undies too, Stiles, you know how to take those off."

Stiles rolled his eyes again (he did that to Derek a lot), "I know how to take _all_ my clothes off, Dad," he insisted, even though he usually got horribly tangled in his shirt and ended up calling for Derek anyway. The little y-fronts were safe enough though, Stiles actually could take those off himself.

Stiles hurriedly pulled them down and stared impatiently up at Derek. "Hurry up," he demanded, "I wanna bath."

Derek chuckled a little, tugging off his own sweatpants (nothing underneath of course), folding all their clothes neatly and placing them on the sink before tugging Stiles back into his arms and stepping into the bath. He sat carefully, Stiles on his lap for a second before he let him slide between his legs. Stiles sighed happily and Derek bent a little to sniff at his boys hair, hands enveloping Stiles' tiny little arms.

"Duckie?" Stiles asked, tipping his head back onto Derek's chest, blinking sweetly at him. Derek bit his lip lightly and reached for the classic yellow duck they kept on the side of the tub. "Thanks, Dad."

"You're welcome, pup."

Derek let them sit in the bath without moving much-except for Stiles playing with the duck and making little "splish, splash" noises-for about ten minutes before he lifted the cloth and started rubbing at Stiles' arms, chest and back, getting all the sleep sweat off of him. Stiles hummed and sighed happily, wiggling a little as Derek cleaned his legs.

"Spread your legs a little for me?" Derek asked, gently washing around Stile's penis and nudging him until he could wash along his butt and his hole. Stiles grunted a little, like he usually did. "Okay, pup?"

"Yeah, s'rough," Stiles replied, frowning down at his penis as he got a little erect. "Why's that always happen, Dad?"

Derek shivered a little, dropping the cloth and shifting Stiles until he could wet and wash his hair. "You're young yet, Stiles. It happens to all boys. It gets different when you're older." He tipped Stiles' head back and rinsed the shampoo, careful around his eyes.

"It happens to you too, sometimes in the bath or in bed," Stiles said, squeezing his eyes shut. "Looks different though."

Derek nodded, running his fingers through Stiles' hair. "I told you, it gets different. Because I'm a grown up, it looks and is different then yours, because you're still a boy. You'll understand in a few years," he assured him, seeing the pout coming. Stiles, more then any other little boy, hated being told he wouldn't understand but this really wasn't something Stiles would understand until he was perhaps ten or eleven, at an age where he discovered that touching himself felt _good_ and that his penis was for more then just pee. Right now it was just a natural reaction, Derek reminded himself, and in a few years he would teach Stiles how to touch himself (oh man, just the thought made him get a little hard)(so wrong, so wrong but God, Stiles was his Mate, not just his son).

Stiles still pouted a little though, even when Derek handed him the cloth and let him wash Derek's chest (so selfish, felt so good though). Derek washed himself after that, taking them both out of the tub and drying Stiles quickly.

"Go pick out some clothes," Derek said, wrapping his own towel around his waist, resting his hand on top of Stiles' head and nudging him towards the door. "I'll help you get dressed once I have my own on."

Stiles sighed dramatically but smiles and left the room, dripping a little on the hardwood floor in their room as he dashed to what was essentially his own room (but he never slept in there, always choosing to sleep with Derek in their big bed).

Derek stared down at where his towel was tented from his growing erection. The sick feeling was still sitting in his gut (as it always was) but it got less and less as the days and years went passed. It was wrong in many ways, he knew that. But Stiles was still his Mate, young or not- _son_ or not-and the wolf always triumphed in his guilt trip.

**

After a quick struggle with Stiles' clothes and happily unhealthy breakfast, Derek dropped Stiles off at school for the day (smiled happily when Stiles threw his arms around his neck and kissed his cheek) and hurried over to the garage he worked at, already wishing for time to pass quickly so he could pick his son up and take him to the safety of their home, their den. He'd decided after that morning (or rather, his wolf decided as he willed his erection to go away), that he would take his first baby step in claiming his young Mate tonight. Something that nobody but themselves would be able to sense. A sort of birthday present, he decided. His wolf grinned.

He swallowed back the sick feeling and let himself focus on his wolf, on the warm feeling his son and Mate created. It would be okay, he assured himself. Everything would be okay.

**

Fancy supper eaten and dishes done, stories of Stiles' super awesome day told and laughed at, Derek told Stiles that he had a special birthday present for him while they cuddled on the living room couch, watching cartoons.

"Present?!" Stiles cried, sitting up quickly and making grabby hands at Derek. "Where?!"

Derek swallowed nervously, nodding towards the stairs. "Upstairs, in bed. It's not something you can use," he warned his excited boy, "or something you can brag about. This is... this is a secret between me and you, okay? You need to promise me that you won't tell anybody."

Stiles stopped bouncing in his lap, head tilted as he looked at Derek. "Why?"

"It's... a present that not many people would understand. You're still very young so it needs to be a secret. Just us."

Stiles stuck his lips out, nodding solemnly. "Pinky," he promised, holding out his little pinky finger. Derek smiled shakily, locking his much bigger pinky with it.

"Pinky. Okay, let's go upstairs," he said, lifting and carrying the boy upstairs, placing in on their pillows at the top of the bed. Derek took a deep breath. "So this morning, when you were asking questions about your penis, and mine and I said you'd understand in a few years?" Stiles nodded at him, frowning in confusion. "Your present is that I'm going to tell you it now instead, and I'm going to show you how mine is different from yours."

Greedy with the thought of illicit knowledge, Stiles nodded quickly, grinning. "You have to remember the pinky though," Derek warns, cupping the back of Stiles' head, "this isn't something most Dad's show their sons, so people wouldn't understand. We aren't like most Dad's and sons. My wolf and I... we need to show you this. Okay?" When Stiles nodded again, Derek squeezed his head gently before plucking at the graphic t-shirt he was wearing. "Take your shirt and jeans off," he told him, stepping back to take his own tight Henley and jeans off, trusting Stiles to struggle his own way out.

Sure enough, Stiles did struggle with the jeans, but eventually managed to tug them all the way off, looking up at Derek, a little confused but so very trusting. Derek stood there, completely naked and let himself look at his sweet little boy, feeling his groin start to stir.

"Undies too, and then lay down, like we're going to sleep," Derek told him, reaching down to cup his dick, not stroking yet, but just touching. Stiles slowly complied, watching Derek's hand.

"Dad?" he asked, undies off and laying down flat on his back. Derek knelt beside him, running his free hand over his head.

"You know how my wolf and I need to mark you? So that way you smell like us to other wolves?" Derek asked, letting himself stroke gently, guiltily enjoying having Stiles watch him. Stiles nodded and Derek kept gently touching Stiles' fluffy soft hair, his pale throat and back back up. "Well, what I'm going to do, what I'm going to show you is kind of like that. My wolf and I want to mark you in a new way, a way that feels really good to us. It's what will happen to you in a few years, you'll start touching yourself like this," he told him, fully hard in his hand. He let Stiles look. "See how I get bigger? There is a lot of blood in my penis right now, and when I touch myself like this," he gave a full length stroke and shuddered out a breath, "it feels really good."

Stiles watched, wide eyed. "It's so big," he whispered. "Will mine get that big?"

Derek chuckled, stroking himself again, thumbing at Stiles' pink lips. "You might, if you grow into those big feet of yours. You might even get bigger then me."

Stiles' eyes grew even wider. "No way!" He looked down at his own penis. "I'll never be as big as you, Dad." He paused, head tilted into his usual 'hush, I'm thinking' pose.

"What is it, pup?" Derek asked, allowing himself to stroke a little faster as he traced the freckles across Stiles' cheeks and throat.

"Can... can I touch it?"

Derek moaned softly, his hand tightening on his cock as his hips jerked. "Stiles."

Taking that as a yes, Stiles reached up, laying one small hand on the head of Derek's cock. "You're leaking!" Stiles exclaimed, pulling his hand away again. "Are you going to go pee?"

"No," Derek gasped, greedily pulling his sons small hand back, showing him to rub at his weeping slit, "no, Stiles, this is a different kind of leaking. It's good, it's very good," he cleared his throat, biting his lip as he watched Stiles' face as his hands explored his cock gently, rubbing and touching him all over. "You see lower, my balls? They carry something called sperm, it helps make babies. When it gets s-so good that you can't hold on anymore, it comes out the top, the part that's leaking. It feels so good right now that a little bit is coming out." Derek honestly didn't know if Stiles was even hearing him anymore, he was so intent on touching Derek's cock and balls, exploring and learning. He seemed to really like when Derek splurted precome because he kept rubbing at the slit and grinning.

"Feels funny," he giggled, dropping his hands onto his stomach when Derek's own hand sped up, giggling harder when a line of precome stuck between his hand and stomach. "Sticky!"

Derek groaned, free hand still touching Stiles' face as he began fucking faster into his fist. He needed to come on his son, his Mate, soon.

Stiles watched, fascinated, lips parted and eyes wide. "Does it still feel good?"

"So good," Derek moaned, hunching over slightly as he felt his orgasm building, "so good, Stiles. Pup, pup, I'm g-going to mark you now, okay?"

Stiles nodded, eagerly watching.

Derek tossed his head back on a rough growl, fucking into his fist as he came all over Stiles' stomach and chest, relishing the noise of surprise his son made at the warm, sticky come now marking him.

It was a few seconds before Derek came down, panting and wolfishly pleased with himself for marking his Mate in his seed ( _his_ seed, _his_ come!) and when he finally tipped his head back down, he felt his cock twitch in his head as he watched Stiles play with the come on him, still fascinated.

"Even more sticky then the stuff before," he said, rubbing it into his belly button with a laugh, "was warm but 's cooler now."

Derek licked his lips, breathing hard. "Can I lick it off of you? It'll be like when I lick chocolate from your face when you make a mess with ice cream, only on your belly." When Stiles nodded, so innocently not understanding how very taboo they'd gone (can't turn back now, marked Mate with seed, mineminemine) and Derek ducked his head, giving long licks from Stiles' hips up to his chest, sucking and licking fervently at his little belly button to get all the come from it.

Stiles laughed and squirmed, squealing with delight. "Tickles!" he shrieked, gripping at Derek's hair. "Dad! Tickles!"

Derek found himself grinning into Stiles' chest. "Sorry pup, had to get it all," he told him, sitting back again.

Stiles looked at his dick again, head tilted again as he kept grinning. "It's smaller again."

Derek nodded, letting go of his dick and laying down beside his son, letting him cuddle into him (still a little sticky, but they'd scrub extra hard in their morning bath). "This is what it looks like when it's soft, like yours. What it looked like before is when it's hard, when it's full of blood. It looks like that when I'm really excited, when it feels so good that I have to touch myself."

"When is it going to happen again?" Stiles asked, yawning into Derek's warm chest. Derek huddled him closer, cupping his little bum and moving him right against him.

"Happens all the time."

"Will you mark me again?"

Derek pressed a kiss to the top of Stiles' head. "Do you want me too?"

Stiles nodded. "Was fun."

Derek breathed heavily, feeling his wolf huff happily. "Okay, pup. We'll do it again."

**

_Beacon Hills, CA  
2008, Stiles' Thirteenth Birthday_

Derek couldn't believe that today his little boy was turning thirteen! A teenager! So much time had passed and yet it still felt like yesterday that Laura was begging him to lie for her and then he was holding his baby Mate in his arms. It felt like minutes ago that Derek had marked Stiles for the first time, had let his boy touch him, had come on him. Seconds since Stiles was ten and Derek taught him how to touch himself, how to bring himself pleasure and kissed him for the first time, which soon became something Stiles demanded hourly (in private). A heartbeat since Stiles turned twelve and Derek finally allowed them to touch themselves while in bed together (but not touching each other, not like that. They'd jerk off side by side or, sometimes with Stiles sitting on Derek's stomach. Derek kissed him before and after with tongue, but that was it). A breath since Derek told Stiles that while he was his son, he was also his Mate and that it was something that they needed to keep between themselves, always in private and that Stiles could call him Dad or Derek, it was his choice.

Thirteen. Jesus.

"Stop thinking," Stiles muttered into Derek's chest, snuffling sleepily. "'S too early for th'king. Sleep."

Derek smiled softly at his son, nuzzling into his hair. "Happy birthday," he whispered, bracing for the flail he knew was coming.

Stiles shot up, eyes wide and dazed. "What?" he demanded down at him. Derek just grinned. Stiles punched his chest. "Derek! What did you say?!"

Derek laughed, tucking his hands behind his head. "Happy birthday, pup."

Stiles shrieked happily, fist pumping before kissed Derek quickly, wiggling in the spot like the excitable pup he'd always been. Derek kissed back, swiping his tongue along his sons sweet little cupid bow lips.

Stiles grunted, grinning and sat up again. "You know what that means, Dad," he said, ripping the sheets off the bed, displaying both of their naked bodies. He ran one hand down Derek's muscled chest and stomach, making him shiver. "You promised. You said when I was thirteen."

Derek flexed his arms, catching the look Stiles always gave them when he did so, and smiled. "Are you sure, pup?"

Stiles, his heart jumping in his chest with nerves (Derek could tell, could always tell), slid on top of him, straddling his waist and making his cock stir. "I've been sure since last year, Derek," he assured him. Derek couldn't help but be proud of his boy. So nervous, so eager, so _his_. "Since you told me what I'd get when I turned thirteen."

Derek slid one hand from behind his head, gripping Stiles' waist, thumb brushing his sharp hipbone. He was still so much smaller then Derek, a sight that made Derek shiver in delight. His boy was growing, that much was obvious, but he was still so _small_ compared to Derek. Even his cock, which had grown in length over the years, was still not near as thick as Derek's. Of course, Derek was pretty damn thick but still. It made Derek hot under the collar (if he was wearing one) to see the difference in their sizes, especially when his wily pup was straddling his waist.

Stiles wiggled a little again, making Derek lick his lips, watching as Stiles' eyes dilated in arousal and his now teenage cock filled. Derek's hand squeezed gently.

"Did you decide then, what you wanted? If you've had all this time to pick one thing we'll do, you must have thought of everything," Derek teased, smirking up at his boy. He knew that Stiles had been thinking of it because Stiles often blurted his ideas and wants out when they jerked off together late at night. Derek had heard each option spoken in breathless detail and he found himself eagerly awaiting Stiles' final choice. Something new that they could do for another year, as was now tradition.

Stiles flushed, settling on Derek's stomach (his favourite spot). "If... if this is the only thing you'll let us do this year," he spoke hesitantly, very different from his usual blabber, "can I make a request?"

Derek nodded, moving his other hand so both hands gripped his boys waist. "You can ask but I can't promise it'll be followed through with. You know my rules."

"I know, Dad, I know. I just... since we've been jerking off together since last year I was thinking that on top of what I chose, we should still do that only... too each other?" he asked, biting his lip and not looking Derek in the eye. "It's not breaking your rules, not really, so..." he shrugged.

Derek thought about it. It would be nice to touch Stiles a little more while they got off together. "We'll start slow," he agreed after a minute.

Stiles sighed happily, slumping down and kissing Derek softly. "Thanks, Dad. 's hard always being right next to you or sitting on you and not getting to touch you."

"I know," Derek murmured against his lips, giving them a little lick before pulling Stiles back up straight. "So," he started, a slow smirk starting again, "my birthday boy. Thirteen. Thirteen times this year we get to do something new. What did you pick for your present, pup?"

The reminder of his present caused Stiles' cock to plump back up to full hardness and Derek shifted a little, getting harder himself.

"I... Dad, I want..." Stiles stuttered, hands fluttering over Derek's chest and nipples. His face went pink and Derek rubbed his hands soothingly along Stiles' sides and hips.

"What, Stiles? What do you want for your birthday?"

Stiles took a deep breath, amber eyes meeting Derek's own green. "I want... you to kiss me... down there," he whispered, looking down at his hard dick, blushing madly.

Derek groaned, hands tightening on his boys hips. "You want me to suck you off, pup? To kiss and lick at your pretty little cock?"

His son moaned, hips jerking slightly, "Yeah," he whispered, "yeah, Dad, please."

As gently as he could, Derek pulled Stiles until his son was sitting on his chest, red cock nearly poking at his lips, sweet boy balls resting on his collarbone. Derek blew a soft breath and Stiles moaned again. "And after I suck you, pup? What then?" he prompted, holding onto his hips tightly so Stiles couldn't thrust, couldn't move.

"I... I'll k-kiss you there too," Stiles gasped. "I'll s-suck you too."

Derek nodded, tilting a little to kiss at Stiles' weeping cock. "That's my good boy," he breathed, feeling drunk of the smell of his sons musk so close to him, so nearly there. He just, he needed to taste him now.

He stuck his tongue out, just touching the wetness and making Stiles cry out, hips straining against Derek's grip then whimpering when he couldn't thrust. Derek licked him again. "I'll teach you," he said, breathing in deeply, "I'll teach you how to suck me, how to swallow me down. I'll show you how to hold off, how not to come right away because, my beautiful little pup, you aren't going to last long in my mouth."

"Dad," Stiles begged, hands digging into Derek's hair, trying to tug him closer. "Dad, please!"

Deciding to show mercy on his birthday boy, Derek wrapped his lips around Stiles, using his tongue gently and sucking just a little, just to show Stiles a little taste. Stiles still cried out, eyes screwed up tight in pleasure. Derek flicked his tongue across his sons slit over and over, relishing the pure bitter flavour after so long of imagining it. Pure Stiles. 

God, Derek thought with a groan, he could only imagine what his little ass was going to taste like.

Derek made Stiles get used to feeling his tongue and the slight suction before he'd release his hips. He tipped his head back, wetting his lips. "Do you want to thrust into my mouth, pup?"

Stiles nodded frantically, "P-please, Dad, please!" He twisted and tugged at Derek's hair, making Derek shiver and moan.

"Okay, okay, you can fuck my mouth and come down my throat. You'll be marking me inside just like I've marked your skin before," Derek said huskily, so unbearably turned on it almost hurt. Stiles groaned at that and Derek knew he liked the thought. "That's my pup," he praised, angling his head just right, opening his mouth and letting go of Stiles' hips.

Stiles fucked forward frantically in the way that inexperienced and selfish teens usually do, wanting only to feel the heat and wet and tightness of the mouth around their cock and Derek just swallowed his down, barely even choking around his sons sweet cock.

As Stiles humped into his mouth, Derek allowed himself to trace the freckles and moles that dotted down his pale soft skin. He tweaked the little brown nipples, making Stiles thrust deeper and Derek just moaned.

"Dad, dad, d-dad, daaad," Stiles chanted, head thrown back in ecstasy, "fuck, Dad! I.. I'm gonna... S-soon."

Derek pinched and rolled a nipple in reply, making Stiles shout, thrust deep and come down Derek's spasming throat. Derek choked a little but quickly swallowed, frantic to get his sons-Mates-come down inside him. Stiles continued to writhe, thrust and moan on top of him, so Derek kept sucking around him, pinching his nipples until Stiles let go of his hair and swayed back. Derek brought his knees up so Stiles could lean backwards without falling out.

Derek watched greedily as his boy panted, heaving great breaths in and releasing them shakily, hands limp at his sides. He couldn't help but thrust a little against his back, needing just a little bit of friction, just enough to relieve a little of the tension building.

"Daaaaad," Stiles groaned, skin still twitching, heart still pounding. "That was... the best present... _ever_."

Derek chuckled, stilling his hips, "Dirty little boy," he crooned, enjoying the flush on Stiles' skin (all over his skin). "Enjoying your daddy sucking your cock."

Stiles' cock gave a little twitch. Derek knew just how much the dirtybadwrongsoright aspect of their relationship got to Stiles (as he'd admitted while jerking off beside him) and didn't feel the slightest bit guilty using it for their own pleasure.

Derek gave him a few more minutes before his own need grew too great and he had to nudge at the drowsy boy. Stiles shifted, eyes blurry but open. "Second part of your present," he reminded his son, hips jerking so that Stiles could feel the hard length against his lower back.

"Oh," Stiles breathed, eyes widening as he slowly shifted off of Derek, mouth open as Derek guided him to kneel between his spread legs. "Right."

"Bend over, curl up a little," Derek instructed, "it might hurt your back after awhile but it'll be good to start. Put your elbows just there, that's right. Perfect, just like that." He ran his hand through Stiles' sweaty fringe, feeling so proud of his boy. "Now just do what I did, kiss it a little, maybe lick it."

Stiles did as told and Derek eyes fell half shut, his breathing going coarse. "That's it, pup, lick it like that. Yeah," he groaned as Stiles licked over his head. "Hold onto the base of my cock if you don't want it to move around on you." Stiles did so, stroking a little and Derek groaned again. "Fuck pup, I need you to try and suck me now. Don't worry about taking it all, j-just focus on... yeah, fuck," he swore as Stiles took the head into his sweet little mouth, "yeah, like that, fuck. Pup, I w-want you to swallow my come b-but you don't have too."

Stiles lent back a little, still stroking the base of Derek's dick and pouted a little at him. "I want too," he insisted.

Derek moaned, tangling one hand in Stiles' hair and gently tugging his pouting lips back to his cock. "Y-you're the birthday boy," he whispered, hips twitching when Stiles grins against his tip. "Suck me, pup."

Stiles does as asked and begins to suck sloppily around the head, saliva slipping down his cock, letting Stiles' hand move smoother as he strokes him in time with his sucks.

It isn't long before Derek finds himself begging his boy, his beautiful little boy, to make him come. Urging and coaxing, petting through his hair and touching his puffy lips wrapped around his cock and looking at his adoring eyes.

"Please," Derek begs again, panting, trying so hard to keep his hips still, "suck harder, puppy, st-stroke faster. Yeah, Jesus," he swears when Stiles listens, "I'm gonna mark you," he warns and Stiles hums, humping his once again hard cock into the sheets like a, fuck, like a little pup. Derek swears again as he comes into his boys mouth, swearing and growling in delight as Stiles chokes a little and struggles to swallow it all down, leaving him panting into Derek's groin, humping madly. "Gonna come again, sweet boy? That's it, you can do it, just touch yourself, use the hand that was just on my cock," Derek demands breathlessly, watching hungrily as Stiles hurries to comply, crying out as his slick hand wraps around his cock. Derek keeps petting his hair, saying sweet and dirty things as Stiles humps and fucks into his hand, eyes tearing up against Derek's soft cock as he stays hunched over. "Come for me, sweet pup. You're so perfect, so good, my little boy. My Mate. I love you so much," Derek whispered softly.

"L-love you, D-dad," Stiles stuttered out, hand moving faster along his cock.

"Come."

Stiles does.

**

_Beacon Hills, CA  
2011, Stiles' Sixteenth Birthday_

In a repeat of Stiles' last Birthday, Derek wakes with a moan on his lips as his boy sucks him off slowly under the sheets.

"Stiles," he groans, hands sliding down to tangle in his hair, urging him back up the bed. Stiles protests but goes silent when Derek kisses him hard, tongue fucking into the sweetness of his boys mouth, tasting himself and allowing the wolf to growl softly. "Happy sweet sixteen," he mutters against Stiles' lips, grinning a little when Stiles wiggles.

"Present now, right? You aren't going to make me wait like last year, right?" When Derek pauses, Stiles sits up with a whine, grinding his ass slowly against Derek's cock. "Dad, you promised! You said you'd finally claim me today and I am so not waiting until tonight to get fucked."

Derek growls lowly again, just thinking about finally getting to bury his cock inside the ass of his special pup. "Stiles, we have a full day planned," Derek reminds him, just to hear him whine. "Grandpa and Grandma are coming over after lunch, Auntie Laura will be here for supper when your friends get here. We might not be able to cover up the smell of us together."

"Don't care," Stiles pouts. "You made me wait until almost midnight last year before you fingered me and I don't want a repeat of popping boners all damn day!"

Derek chuckled, hands absently stroking his sons sides, trying to soothe the boy. He has grown so much, Derek thinks with a small sigh. Nearly the same height now, with Stiles finally growing into his hands and feet (and cock, which is long and thin, just like the rest of him). Still so small in his arms though, he thinks proudly. So safe in his dad's arms.

"Scott was pretty scarred," Derek remembers with a grin, thinking of Stiles' long time best friend. "He thought you kept getting them for him."

Stiles rolled his eyes in time with his hips, making Derek hum and his hips twitch. "He's a moron," he says fondly.

Derek agrees, but doesn't say it, choosing to pet Stiles all over his pale skin, feeling the slight muscle twitch under his hands. Stiles sighs, still grinding slowly, lifting one hand to stroke his dick to full, aching hardness, a glint of mischief alighting his golden eyes. He gives a low moan, biting at his plump pink lip. His free hand reaches up to tweak his nipple.

"Bet I could always find someone else to claim," he teases, knowing that Derek hates the very thought of someone else touching him. "Maybe Isaac would be willing to be my first?"

Derek growls in warning, eyes flashing blue as they always do when Stiles purposefully makes him jealous, the little shit. Stiles' heartbeat picks up in arousal and even though Derek knows its for him, his wolf snarls at the mere thought it could be for someone else. They learnt not long after Stiles turned fourteen and kissed Lydia Martin at school that Derek gets very possessive when Stiles even hints at someone else. Apparently the kiss had been a test for Stiles to see just how far he could push Derek. In reply, Derek rimmed Stiles for so long that night that he's cried and begged and eventually passed out after his third orgasm.

"Isaac is so adorabs," Stiles continues, licking his lips, "with all the curly hair and his silly scarves. Such sweet eyes. And those lips, fuck, bet they'd feel so good wrapped around my-"

Derek flips them over, slamming his mouth against his sons, stopping the horrible flood of words, even knowing that they're lies and the brat is saying it simply to get what he wants, but he needs to stop the lies before he does something drastic like bite him right where anyone can see (instead of the bruises lining his hips and inner thighs).

Stiles groans in triumph, arms locked around Derek's neck, legs wrapping tightly around his waist. "Dad, please," he sighs when Derek pulls back enough to let him talk.

"Nobody else," Derek growls, biting and tugging at Stiles' lips, "nobody!"

Stiles nods frantically, clawing down Derek's back, "Nobody else, Dad, nobody else ever. Love you so much."

His wolf howls and Derek has to tip his boys head back to sniff and lick at the vulnerable skin there, forcing his teeth back to normal and moving his hands to stroke and touch and pinch at the expanse of skin under him. "Want me to claim you, pup? Want me to fuck you so hard you're limping for the rest of the day?"

Stiles moans, nodding again. "Please. Dad, Derek, please!"

Derek quickly gets the ball rolling, gently turning Stiles onto his stomach, legs spread wide in their favourite position so he can get his mouth on the tight little pinprick. He licks and licks and licks all over Stiles' crack and hole until Stiles begs again, and only then does Derek tighten his tongue to fuck inside. Stiles clenches around him but is quick to loosen with a low moan, burrowing into the pillows and wiggling.  
Derek soon loses track of time, everything slowing down to just his sons manly musk suffocating him, his taste choking him until Derek feels like he could blow his load right then and there. But no, no it's his boys sixteenth birthday and he promised him that he'd finally fuck him today and he is damn well going to fuck him.

Pulling back a little, he quickly sucks on his middle finger, getting it nice and slick before sliding it easily into Stiles' already slightly loosened hole. Stiles groans into the pillow, lifting his hips slightly, trying to get the single digit deeper. Derek complies, slowly twisting and thrusting his finger as he leans over onto the end table to grab the lube.

"You're going to take four today," Derek tells him, squirting a dollop of cool lube onto his thrusting finger, working it in deeper and making the glide so much easier. Stiles lifts his head, sounds of protest already spilling from his swollen lips but Derek thrusts his finger in fast to quiet him. "I need to make sure you are stretched. I won't hurt you, I won't," he urges. Stiles' head drops back, biting the pillow. Derek takes this as a sign to gently add another finger and Stiles tucks his knees under him, lifting his ass off the bed. "That's it, you're so good at this, pup. Been doing this to you for a year, you know how to take my fingers so well," he praises, so proud of his boy.

"'nother," Stiles slurs into the pillow, "ple'se, Dad. 'nother f'nger."

"My birthday boy," Derek grins, scissoring his two fingers slowly and gently a few times before giving Stiles what he wants and adds the third finger, twisting and turning them inside his tight ass as Stiles keens loudly, clenching down so tightly around his fingers before relaxing. "Gonna feel so good around my cock, so perfect. My perfect Mate, my perfect son."

Stiles moans and groans for him, his cock dripping precome between his legs, making a mess of the sheets under him. Derek crooks his fingers and Stiles shouts, jerking back into Derek's fingers.

" _DAD!_ " He cries, coming untouched as Derek fucks him faster and a little harder with the three fingers, hitting his prostate relentlessly. " _Fuck!_ "

Derek kisses and bites at the lovely dip in Stiles' back as his son trembles under and around him. "Soon, pup, just one more finger, okay?"

Stiles spreads his knees as wide as he can when Derek adds more lube, sobbing as Derek slips his pinky finger into the loosened hole.

Derek continues to finger him, going harder and faster when Stiles relaxes before he can't take the wait anymore and slowly drags his fingers out, slicking up his aching cock. He grips Stiles' hip with his clean hand and presses the tip of his cock against the winking flesh, swallowing hard and hesitating. "Do... do you want me to wear a condom?"

Stiles snorts, gasping for air as he tilts his head out of the pillow. "'s only you. Only ever you. No condom. Wanna feel you."

Derek moans, a low growl building up in his throat as he slowly (so slowly) slides inside his boy, his son, his Mate for the very first time.

Stiles wails in pleasure, gripping the pillow so tightly he nearly rips it and Derek has to let go of his hip so he won't claw him by accident, reaching for the headboard and digging his claws in there.

He was right, he was so right. Stiles feels so perfect around him, so tight and hot and wet. He can feel his walls pulsing around his cock as his young body gets used to the intrusion.

It's all a haze after that, for the both of them.

Derek thrusting as gently as he can at first until Stiles demands he go faster.

Fucking into him like he's wanted to do (guiltily) for years, hard and _claiming_.

Stiles crying because it feels so good and right to have his Dad fucking him, then having Derek pull him up, stretching him so he can lick and kiss at the tears streaming down his face, promising his son he'll take care of him, he'll always take such good care of him because that's what Dad's do, that's what Mates do.

Stiles coming a second time untouched as Derek pounds into his prostate again and again and again, making him promise to always be Derek's (which Stiles babbles out as fast as he can and Derek can hear the truth in his words, in his pounding heartbeat).

Derek coming deep inside his boy, pushing him back to the bed so he can bite at Stiles' shoulder blade, a mating mark that nobody will see, nobody but them. He promises in return to only ever love Stiles, to never have anybody else, to never even want anybody else.

It's always been Stiles and Derek and it always would be.

 

**


End file.
